THE DOORS OF THE FIREHOUSE SWING OPEN AND A 1949 open-cab, diesel Autocar pumper capable of spewing 1,000 gallons of water per minute roars to life as Lawrence Gaddis wheels out and heads down the street.

But wait! That's not a fireman clanging the bell for him, that's a kid. In fact, there's a whole gaggle of kids aboard blowing sirens and flashing lights and, as Gaddis puts it, "squirting water" up and down the length of a few Rockville blocks.

"They're really tickled," he says, in what appears to be an understatement, describing the would-be firefighters' feelings about playing pretend in the private firehouse of retired Montgomery County fire captain Lawrence Gaddis.

Gaddis looked at 340 county houses before he found just the right one with enough land on which to create his authentic 2,700-square-foot, three-bay station, which can accommodate six trucks. He settled on five adjoining parcels of land on Anderson Avenue in West End Park. Today his collection includes four fully operational antique fire engines (circa 1937-1958), 500 sirens and lights, nozzles, helmets, hundreds of radios, brass fire poles and fire extinguishers from the early 1900s, including one tube that scatters a chemical similar to baking soda. In the 10-by-10-foot watch office, there's even a radio console on which Gaddis can sound tones that simulate dispatch calls. The firehouse looks so real UPS drivers and tourists stop by to ask directions.

Still Gaddis thinks "it will take the rest of my life to organize completely the hundreds and hundreds of items I have here. I don't want a junkyard but a meaningful display." Gaddis, recently elected deputy fire chief of the 200-man Rockville Volunteer Fire Department, just can't seem to get firefighting out of his blood. He first began hanging around firehouses at age 10, washing engines, running errands and going to fires on his bike -- "frequently beating the fire trucks," he is still moved to mention.